Measurements of complex permittivity and permeability with changing an angle of incidence of parallel beam generated by dielectric lenses

When using an automotive collision avoidance radar or a communication system with other automobiles or with communication points on the roadsides, electromagnetic (EM) wave reflection from the road surface and from fences beside the road may cause disturbance in the communication. Therefore, the road and any fences along the road must have large EM wave absorption effects. If the complex relative permittivity epsiv_r(epsiv_r) and the value of the complex relative permeability mu_r(mu_r) of a large flat plate can be measured by the free space method, it would be easy to develop roads and fences that have large electromagnetic wave absorption.This paper presents: a) measurement theory of epsiv_r and mu_r by using large flat plate, b) plane wave method using dielectric lenses, c) measurement technique of a epsiv_r and mu_r,and d) the results agreed with the ones obtained by an S parameter coaxial line method.